Electronic data storage is rapidly replacing paper storage as a preferred mechanism for storage of information. Additionally, electronic data storage provides the ability for users to store and access data remotely through a network, such as the Internet. With such a reliance on electronic data storage, storage systems must provide constant availability and high reliability.
In order to ensure reliable performance, storage systems employ redundant systems. For example, data is stored in multiple locations such that should one storage device fail, a redundant set of data may be accessible on another storage device. Another type of redundant system is the use of multiple power supplies. Storage systems receive power from power supplies during operation. If a power supply fails, a redundant power supply may provide power to the storage system without losing storage system availability.
A problem associated with redundant power supplies is the summation of available output currents of multiple power supplies. When a catastrophic failure like a short circuit occurs, the available short circuit current is the total amount of current for each power supply. This amount of current may damage components within the storage system and may cause a catastrophic failure. While individual power supplies typically include overcurrent protection, when power supplies are coupled in parallel, an overcurrent condition may occur which would not be prevented by each power supply's integrated overcurrent protection. Consequently, a method and system for preventing an output of current greater than a desired level from redundant power supplies is necessary to avoid damage to components from high current while ensuring redundancy.